Galactic C and S Stars as Guidelines for Magellanic Cloud AGB Stars

Abstract

The study of the evolutionary properties of Asymptotic Giant Branch stars still presents unresolved topics. Progress in the theoretical understanding of their evolution is hampered by the difficulty to empirically explain key physical parameters like their luminosity, mass loss rate and chemical abundances. We are performing an analysis of Galactic AGB stars trying to find constraints for these parameters. Our aim is of extending this analysis to the AGB stars of the Magellanic Clouds and of the Dwarf Spheroidal Galaxies using also mid-infrared observations from the Antarctic telescope IRAIT. AGB sources from the Magellanic Clouds will be fundamental in our understanding of the AGB evolution because they are all at a well defined distance (differently from the Galactic AGBs). Moreover, these sources present different values of metallicity: this fact should permit us of examining in a better way their evolutionary properties comparing their behaviour with the one from Galactic sources.